Objective To investigate the role of expression in the differential diagnosis of thyroid follicular carcinoma and follicular variant of papillary carcinoma. Methods Seventy cases of thyroid lesions (including 15 cases of follicular adenomas, 15 cases of adinomatous goiters, 30 cases of papillary carcinomas and 10 cases of follicular carcinomas) were collected, and CD10 expression was detected by means of immunohistochemistry in above thyroid lesions. Results Seven of 9 cases of follicular variant of papillary carcinoma were CD10 positive (77.8%), and 8 of 10 cases of follicular carcinoma were CD10 positive (80.0%). However, CD10 was negative in all cases of non-follicular variant of papillary carcinoma, follicular adenoma, adinomatous goiter and normal thyroid tissue. Conclusion The detection of CD10 expression is useful to the differential diagnosis of thyroid follicular carcinoma and follicular variant of papillary carcinoma.